The use of a silica (SiO2) and carbon (C)-containing material as starting material for silicon carbides or silicon is known.
An example of a known method for producing silicon carbide using a silica and carbon-containing material involves heating inexpensive silica and a carbonaceous material such as coke as the starting materials to 1500 to 1900° C. so as to induce a reducing reaction between the carbon and the silica and thereby produce silicon carbide of relatively high-purity (see Patent Document 1).
A method for producing a starting material for the production of high-purity silicon using a silica and carbon-containing material involves forming silicon monoxide gas and carbon monoxide gas by reacting a mixture of carbon and a material composed primarily of silicon dioxide at a temperature in the range of 1300 to 1800° C. and under a pressure of 5,000 Pa or lower at the surface of contact between both materials, cooling this gas and solidifying some of the silicon monoxide into a bulk form, then recovering the solidified silicon monoxide, and exhausting the rest of the silicon monoxide (see Patent Document 2). In cases where silicon is produced from silicon monoxide (SiO), the purity of the silicon obtained in the conventional art depends on the purity of the silicon monoxide serving as the starting material. With the method described in Patent Document 2, it is possible to obtain high-purity silicon monoxide that can be used as the starting material for silicon.